The far-right British National Party will take court action after the personal details of thousands of party members were published on a website.

The list includes the contact details of 10,000 individuals, including over 200 people from Birmingham and in some cases their professions, qualifications and hobbies. This year the BNP said it obtained an injunction at the High Court in Manchester banning publication of the list.

Party leader Nick Griffin said: “It was entirely wrongly used without authority by a very small group of previous party members expelled late last year who passed it on, to who we simply don’t know. All we can say is if we find out who it was and they are one of those covered by the High Court injunction, they are going to prison.”

In total, 238 people with Birmingham addresses are listed. They are known to include a retired police officer, a former prison service worker, a pilot and a pharmacist. Children, including two city teenagers, are also on the list because the party has family membership deals. The far-right British National Party has demanded a police investigation into the leak.

Mr Griffin claimed members received threatening calls – calls he said were part of an “established dirty tricks campaign” from the Labour Party.

“There are small numbers of people organised by, motivated by and funded by the Labour Party who intimidate and threaten our members,” he said. “Hundreds of our members have had calls, threatening calls and we have no doubt it’s from the same telephone banks in the offices of unions like Unite who campaign against us and telephone canvass in elections.

"We’re sure that this is a left-wing trick by the unions and Labour Party. The number of calls, the sheer volume can’t come from an isolated number of people.”

He added: “There is an established dirty tricks campaign run by and for the Labour Party, it can only be that.”

Mr Griffin was speaking in the BNP stronghold of Burnley, where he was flanked by party supporters carrying Union Jacks. He claimed the list’s publication was fantastic publicity.

“We couldn’t have bought the publicity, the fact we have teachers and doctors and women that knit, it’s a fantastic event politically for us,” he said.